The present invention relates to an electrophotographic copying apparatus, and more particularly to a mechanism for withdrawing a copy paper transporting unit from the body proper of a copying apparatus.
Generally, a copying apparatus developed in recent years is so constructed that at least a part of the apparatus which is constituted by various elements, such as copy paper transporting means, developing means and cleaning means, is made into a unit for withdrawal from the body proper thereof so as to make inspection of the apparatus, replacement of the photosensitive member or removal of jammed copy paper simple. One example of such a copying apparatus is shown in U.S. Pat. No. 4,017,169 in which a copy paper transporting unit combined with a corona transfer station is mounted for lateral withdrawal from the interior of the copying apparatus in a direction perpendicular to the feeding direction of the copy paper. However, the problem with this unit is that if copy paper is jammed at a position in which one end of the paper is nipped by a pair of feeding rollers and the other end of the paper extends into the unit, the paper may be torn since the unit is withdrawn in a direction perpendicular to the feeding direction of the copy paper. Further problems with this unit are that the mechanisms for releasing the unit from, and for locking the unit with, the copying apparatus are relatively complicated, and their operations are quite troublesome.
Japanese Unexamined Patent Application SHO No. 53-12335 published on Feb. 3, 1978 discloses an image transfer type copying apparatus with a copy paper transporting unit constructed so as to be able to be withdrawn in the feeding direction of the copy paper. Such unit extends from a feeding station, including a paper feeding roller, to an image transfer station or all the way to the paper discharging end. However, in this apparatus, if copy paper is jammed in the vicinity of the feeding roller, the paper cassette, containing a stack of copy paper, must at first be removed in order to extract the jammed paper, since the unit itself includes the feeding roller as well as the cassette.